Like most Americans, I felt a visceral surge of patriotic pride when I heard that we’d killed Osama bin Laden: pride in the President who ordered and orchestrated the bold raid, pride in the military that carried it out, and pride in a nation that, after nearly a decade of half-measures and absurd distractions, finally hit the primary target in the battle against Al Qaeda. We got the sonofabitch. I loathe violence and oppose capital punishment, but I’m pragmatic enough to understand that in some very, very rare cases, the only correct solution is a bullet. This was one of those cases.

But we have to be wary of surges of patriotism. They come from a place beyond reason, a primitive part of our tribal psyches, and leaders of all sorts have exploited them ruthlessly throughout history. As soon as the initial cheering dies down, we must set aside the easy jingoism and force ourselves to ask some hard questions. Exactly what did we just do, what did it cost, and was it really, objectively worth it? While asking those questions, though, we have to appreciate the conditions under which the decisions were made.

Fortunately, more than a year after that fateful night in Abbottabad, this phase of post-game analysis is still in full swing. Many foreign policy wonks bemoan the precedent the raid set: landing troops inside a sovereign nation without permission to carry out what can only be described as an assassination. US relations with Pakistan were fragile before; the two nations are barely speaking now.

Public health and infectious disease geeks like me, meanwhile, have been wringing our hands over a Central Intelligence Agency operation that took place before the raid. At the time, the Agency had a major problem. They’d pinpointed a residential compound where they strongly suspected bin Laden was holed up, but they couldn’t be sure. The man they saw pacing the courtyard in reconnaissance photos could have been him, or could have been some wealthy hermit with no connection to terrorism. When you’re on the cusp of dropping dozens of Navy SEALs into someone’s yard in the middle of the night and triggering an international incident, you really want to be sure you have the address right. The spooks decided to get creative.

Enlisting a Pakistani doctor named Shakil Afridi, the CIA mounted a campaign to collect DNA samples from children in Abbottabad, under the cover of a hepatitis B vaccination program. Afridi deployed nurses first in the slums of the city, then moved the campaign closer to the suspected bin Laden residence. If children from the target house carried bin Laden DNA, it would mean that Osama was most likely there. The effort appears to have failed, but the President ultimately took an enormous risk and authorized the raid anyway.

The public health community has been fiercely critical of this “fake” CIA vaccination campaign ever since. This recent post from infectious disease blogger Maryn McKenna typifies the general sentiment, which was exactly how I felt when I first heard about this incident. Laurie Garrett, meanwhile, took a more sensationalist tone in a shrill (and inaccurate) rant last month.

Other than a snide remark on Twitter when the news first broke, I’ve kept pretty quiet about this story. That’s because when I learned more details of the operation and started analyzing it, I became – and remain – deeply conflicted about it.

Public health has always been the poor cousin of medicine. When it works perfectly, nothing happens. There’s no dramatic moment when the patient’s heart re-starts, no miraculous recovery as the antibiotics take effect, no made-for-TV journey from sickness into health. The gains from vaccination, sanitation, and prevention are enormous and real, but they accrue on statistical tables that are very hard to explain to non-specialists.

As a result, public health workers have spent decades earning the public’s trust, especially among the poor and marginalized populations that suffer disproportionately from preventable diseases. When the amply-funded CIA made the cynical decision to hijack that hard-won trust for a short-term military objective, people in the field were understandably upset. That said, the Agency’s decision was not entirely arbitrary, and its impact wasn’t necessarily as bad as some commentators have implied.

Let’s get some perspective here. This DNA-collection effort was part of a broader project to stop a prolific mass-murderer. Osama bin Laden did not have blood on his hands; he was swimming in it. This was a man who had directly masterminded the deaths of several thousand innocent civilians, triggered a war that killed and maimed tens of thousands, and continued to promote and design attacks to kill many thousands if not millions more. He made no secret of his desire to annihilate Israel, destroy Western civilization, and roll human rights back to the Middle Ages. The only meaningful distinction between bin Laden and Hitler was that the former did not control sufficient weaponry to scale up his plans – yet. Public trust in vaccination campaigns is certainly important, but it is not all-important. Other priorities do exist.

Nor was the CIA’s betrayal a unique affront to public health. Yes, there have been some setbacks in the World Health Organization’s vaccination campaigns in Pakistan since the bin Laden raid, but it’s not clear the CIA caused those problems. Indeed, the polio eradication campaign, originally slated to be done in the year 2000, has been struggling for years. Pakistan isn’t even the toughest challenge for WHO vaccinators at the moment – Nigeria is. The covert DNA screening surely didn’t help matters, but it’s ridiculous to presume, as Garrett apparently does, that everything in public health would be going perfectly if the CIA hadn’t done this.

Finally, while it certainly wasn’t a very well-structured vaccination campaign, and it was clearly done with ulterior motives, it’s probably not correct to refer to the CIA effort as “fake.” As far as we can tell, the Agency obtained and distributed real hepatitis B vaccine. I presume they chose an injected vaccine because it provided better cover for DNA collection than the oral polio vaccine. A proper hepatitis B immunization requires three doses spread out over six months, but partial immunization still provides some protection against the virus. A handful of Pakistani kids may avoid liver cancer because of this. That’s not a justification, just an observation.

So was the hunt for bin Laden ultimately worth the cost? I still don’t know. I do know that it’s neither fair nor useful to judge the entire operation through a single narrow lens, with information that was only available after the fact. The DNA collection may have failed, but nobody knew it would fail at the outset. The President authorized the raid anyway, but given how thin the evidence was, it would have been perfectly reasonable for him to call it off, leaving the world’s top terrorist alive to plot his next attack.

Foreign policy is full of the nuances, tradeoffs, and uncertainties of a deeply imperfect world. We can and should hold our government to account for its actions, and we can and should point out the real harms that come from undermining public health efforts. But a decision can only be bad if another option was clearly better, and in this case I can’t quite bring myself to condemn the CIA’s choice.